蛇毒中鞣花酸类及三萜类成分研究

自蛇毒（ＤｕｃｈｅｓｎｅａｉｎｄｉｃａＦｏｃｋ）全草中分离出６个化合物，其中，２个为新化合物，分别命名为蛇莓甙Ａ（ｄｕｃｈｅｓｉｄｅＡ）和蛇莓甙Ｂ（ｄｕｃｈｅｓｉｄｅＢ），经化学及光谱（ＵＶ，１Ｒ，１ＨＮＭＲ，１３ＣＮＭＲ，ＮＯＥＤＳ和ＭＳ）分析确定，蛇莓甙Ａ的结构为３＇－Ｏ－甲基－鞣花酸－４－Ｏ－β－Ｄ－吡喃木糖甙（Ⅰ），蛇莓甙Ｂ的结构为３＇－Ｏ－甲基－鞣花酸－４－Ｏ－α－Ｌ－呋喃阿拉伯糖甙（Ⅱ）。另外４个化合物为已知三萜类化合物：３β－羟基－乌苏烷－１２－烯－２８－羧酸（Ⅲ），２α，３β，１９α－三羟基－乌苏烷－１２－烯－２８－羧酸（Ⅳ），２α，３β，１９α－三羟基－乌苏烷－１２－烯－２８－羧酸－２８－Ｏ－β－Ｄ－吡喃葡萄糖甙（Ⅴ），２α，３α，１９α－三羟基－乌苏烷－１２－烯－２８－羧酸－２８－Ｏ－β－Ｄ－吡喃葡萄糖甙（Ⅵ）。其中化合物Ⅳ，Ⅴ和Ⅵ为首次从该属植物中分离得到。     

化学—酶法立体控制合成光学纯L-羟基苯丙氦酸的新方法

Optically pure L-3(2-hydroxyphenyl) alanine(L-o-tyrosine ,Ⅲa,),L-3-(3-hydroxyphenyl) alanine(L-m-tyrosine,Ⅲb )and L-3-(4-hydroxyphenyl )alanine(L-p-tyrosine,Ⅲc )were synthesized by the stereocontrolled amination of corresponding hydroxycinnamic acld(Ⅱ)catalyzed by L-phenylalanine ammonia-lyase(PAL,EC4.3.1.5 )contained in Rhodoterula rubramycelium. The amination of compound Ⅱ was completed in aqueous ammonia solution( 6.4mol·L^-1,pH10.5, 30℃) with the conversion of 74.9%(Ⅱa),21.1%(Ⅱb)and 20.6%(Ⅱc)respectively.The absolute configuration of the products Ⅲa～c were confirmed by circular dichroism(CD),and chiral high-performance ligand exchange chromatography(HPLEC)showed that productsⅢ were optically pure L-isomers.